Date   

Re: Need help with issue in RA guiding and Synchronous Pulseguide

Chris H.
 

Good to hear you got it sorted out, Parijat!

Chris

On Fri, May 4, 2012 at 3:03 AM, photonphisher <parijat_singh@yahoo.com>wrote:

**




Progress at last!

I took the 3 gears out from the RA gearbox, cleaned thoroughly and placed
them back. Did not see any noticeable dirt in there but cleaned all of them
re-greased anyway.

And just completed running several hours of tests in PEMPro, imaging and
guiding. So far, the issue has not come back. So either there was something
in the gear teeth (which I could not see) or old grease, or the act of
taking the gears out and assembling back with the pinions. Not sure but the
issue seems to be gone now! :)

Thanks to all who responded with ideas and suggestions...
I think the gears might need more maintenance perhaps than just lube,
maybe cleaning once in a while.

Parijat

--- In ap-gto@yahoogroups.com, "photonphisher" <parijat_singh@...> wrote:

Hi Marj,

Thanks-
The moon is up, so I am not in a big hurry right now....and have time to
do some more tests.

Regards
Parijat


--- In ap-gto@yahoogroups.com, Marj <marj@> wrote:

Parijat,

Roland and I will be back in the office tomorrow and will review your
information at that time. We have been on the road since NEAF.

Marjorie Christen


On May 3, 2012, at 4:28 PM, "photonphisher" <parijat_singh@<mailto:
parijat_singh@>> wrote:




Hi Marj,
In the tracking curve I had uploaded, you can see PEM was always
disabled (red button on the left). So I had ruled that out initially.

http://groups.yahoo.com/group/ap-gto/photos/album/104285095/pic/136447746/view

I think the gears are something I have not cleaned in a year (only
lubricated). They look clean but it I understand from some of the posts
here, it is suspect as it does not take much to cause a 5" irregularity.

Thanks again.
Parijat

--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>,
"marjchristen" <marj@> wrote:


I suggest that you disable the PEM first and evaluate the
performance. The rest of the steps you mention may not be needed if the
problem is dur to an erroneous PEM curve.

Marj Christen

--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>,
"photonphisher" <parijat_singh@> wrote:

Hi Marj and All,

Thanks a lot for your valuable suggestions. I now have a good list
of things to check and ponder on.

I am planning to remove the 3 gears and carefully clean them well,
and apply fresh grease.
Then double check the worm binding, backlash etc.
And disable PEM before checking the tracking.

Some homework to do :)

Thanks again, very much appreciate the help.

Parijat



--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>,
"marjchristen" <marj@> wrote:

Dear Parijat,

Here is another idea. Do you have PEM set to yes? If you do, set
it to "no" and see what happens. Sometimes, people create a bad periodic
error correction model and then when the correction is activated, it causes
strange movement.

Marj


--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>,
"photonphisher" <parijat_singh@> wrote:

Hi Floyd
Yes it happens once per worm cycle. I monitored it for 5
cycles and showed up exactly at the same location each time. I can only
think of the worm/block/assembly but I don't know the internals.

Last night I was seeing dumbells in 30 sec exposures if they
fell in the right (or wrong) window. :(

Parijat



--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>,
"bakersfieldbiker" <fblue@> wrote:

Hi,
Oh, I agree, it was probably not the situation, just was
curious.
This only happens one time per worm cycle?
Floyd

--- In ap-gto@yahoogroups.com<mailto:
ap-gto%40yahoogroups.com>, "photonphisher" <parijat_singh@> wrote:

Hi Floyd,
I moved it 360degrees and it move smoothly with fingers.
The mesh is optimum that there is little or no backlash. Also the screw on
the spur gear is very tight.
That is the only gear in phase with the worm period and I
felt nothing wrong with it physically and moving it full circle. No binding
whatsoever. I would think binding would cause an issue much more prominent
than 5arcsec.

Parijat


--- In ap-gto@yahoogroups.com<mailto:
ap-gto%40yahoogroups.com>, "bakersfieldbiker" <fblue@> wrote:

Hi Parijat,
Did you actually move the spur gear on the worm and this
is where you say it moves smoothly? Just curious, because of an earlier
thread where I described a binding in the worm gear bearing that I found on
the AP-900.
Probably not related, but am wondering.
Floyd

--- In ap-gto@yahoogroups.com<mailto:
ap-gto%40yahoogroups.com>, "photonphisher" <parijat_singh@> wrote:

Hi David,
Thanks for your reply.
I have checked the gears for binding, etc. but they
are all smoothly moving. Hence running out of ideas.

Parijat


--- In ap-gto@yahoogroups.com<mailto:
ap-gto%40yahoogroups.com>, David Holko <dholko@> wrote:

Hello,

About a year ago I had a issue with my AP1200 RA
motor. Howard got on
the phone with me and walked me thru a few checks. I
am sure that once
the staff returns from NEAF you will be able to
contact Howard and he
will do the same. It is not difficult to remove the
top of the RA
housing and see and feel the gears and how the move
with your fingers.
To see if there are binding.
I ended up sending the control box, RA housing and
cables back to AP and
it all got sorted out. No issues since.

Dave


[Non-text portions of this message have been removed]




[Non-text portions of this message have been removed]


[Non-text portions of this message have been removed]


Re: Need help with issue in RA guiding and Synchronous Pulseguide

parijat_singh
 

Progress at last!

I took the 3 gears out from the RA gearbox, cleaned thoroughly and placed them back. Did not see any noticeable dirt in there but cleaned all of them re-greased anyway.

And just completed running several hours of tests in PEMPro, imaging and guiding. So far, the issue has not come back. So either there was something in the gear teeth (which I could not see) or old grease, or the act of taking the gears out and assembling back with the pinions. Not sure but the issue seems to be gone now! :)

Thanks to all who responded with ideas and suggestions...
I think the gears might need more maintenance perhaps than just lube, maybe cleaning once in a while.

Parijat

--- In ap-gto@yahoogroups.com, "photonphisher" <parijat_singh@...> wrote:

Hi Marj,

Thanks-
The moon is up, so I am not in a big hurry right now....and have time to do some more tests.

Regards
Parijat


--- In ap-gto@yahoogroups.com, Marj <marj@> wrote:

Parijat,

Roland and I will be back in the office tomorrow and will review your information at that time. We have been on the road since NEAF.

Marjorie Christen


On May 3, 2012, at 4:28 PM, "photonphisher" <parijat_singh@<mailto:parijat_singh@>> wrote:




Hi Marj,
In the tracking curve I had uploaded, you can see PEM was always disabled (red button on the left). So I had ruled that out initially.

http://groups.yahoo.com/group/ap-gto/photos/album/104285095/pic/136447746/view

I think the gears are something I have not cleaned in a year (only lubricated). They look clean but it I understand from some of the posts here, it is suspect as it does not take much to cause a 5" irregularity.

Thanks again.
Parijat

--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "marjchristen" <marj@> wrote:


I suggest that you disable the PEM first and evaluate the performance. The rest of the steps you mention may not be needed if the problem is dur to an erroneous PEM curve.

Marj Christen

--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "photonphisher" <parijat_singh@> wrote:

Hi Marj and All,

Thanks a lot for your valuable suggestions. I now have a good list of things to check and ponder on.

I am planning to remove the 3 gears and carefully clean them well, and apply fresh grease.
Then double check the worm binding, backlash etc.
And disable PEM before checking the tracking.

Some homework to do :)

Thanks again, very much appreciate the help.

Parijat



--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "marjchristen" <marj@> wrote:

Dear Parijat,

Here is another idea. Do you have PEM set to yes? If you do, set it to "no" and see what happens. Sometimes, people create a bad periodic error correction model and then when the correction is activated, it causes strange movement.

Marj


--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "photonphisher" <parijat_singh@> wrote:

Hi Floyd
Yes it happens once per worm cycle. I monitored it for 5 cycles and showed up exactly at the same location each time. I can only think of the worm/block/assembly but I don't know the internals.

Last night I was seeing dumbells in 30 sec exposures if they fell in the right (or wrong) window. :(

Parijat



--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "bakersfieldbiker" <fblue@> wrote:

Hi,
Oh, I agree, it was probably not the situation, just was curious.
This only happens one time per worm cycle?
Floyd

--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "photonphisher" <parijat_singh@> wrote:

Hi Floyd,
I moved it 360degrees and it move smoothly with fingers. The mesh is optimum that there is little or no backlash. Also the screw on the spur gear is very tight.
That is the only gear in phase with the worm period and I felt nothing wrong with it physically and moving it full circle. No binding whatsoever. I would think binding would cause an issue much more prominent than 5arcsec.

Parijat


--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "bakersfieldbiker" <fblue@> wrote:

Hi Parijat,
Did you actually move the spur gear on the worm and this is where you say it moves smoothly? Just curious, because of an earlier thread where I described a binding in the worm gear bearing that I found on the AP-900.
Probably not related, but am wondering.
Floyd

--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "photonphisher" <parijat_singh@> wrote:

Hi David,
Thanks for your reply.
I have checked the gears for binding, etc. but they are all smoothly moving. Hence running out of ideas.

Parijat


--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, David Holko <dholko@> wrote:

Hello,

About a year ago I had a issue with my AP1200 RA motor. Howard got on
the phone with me and walked me thru a few checks. I am sure that once
the staff returns from NEAF you will be able to contact Howard and he
will do the same. It is not difficult to remove the top of the RA
housing and see and feel the gears and how the move with your fingers.
To see if there are binding.
I ended up sending the control box, RA housing and cables back to AP and
it all got sorted out. No issues since.

Dave


[Non-text portions of this message have been removed]




[Non-text portions of this message have been removed]


Re: Larger "diameter" Counterweights for AP-1600 ?

Joe Zeglinski
 

Thanks Howard, You are correct,

I did get my "Latitude problem" reference, reversed. The weights hitting the pier, would be more likely for a concern with mounts used at LOWER latitudes, closer to the equator.

So, Chuck might have a problem using heavier, "larger diameter", counterweights, at the upper part of the bar. Only solution then would be to use steel encased lead filled cwts .

As a side note, to using something for counterweights, "heavier than lead" - the early NASA Lifting Vehicle M2-F2 (precursor of the Space Shuttle) - needed to shift the centre of gravity, and the engineers briefly ... and incredibly ... considered surrounding the pilot's cockpit with "Depleted Uranium, as ballast, which is much DENSER than lead", to save space - a method, commonly used to balance aerospace vehicles. (ref. Wingless Flight, pg 78). That idea was quickly squashed, by the three main test pilots who didn't like the idea of cooking their feet in radiation - and maybe by the test pilot's wife. :-)

Joe

-----Original Message-----
From: Howard
Sent: Thursday, May 03, 2012 6:13 PM
To: ap-gto@yahoogroups.com
Subject: RE: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?

Hi Joe,

I'm assuming you got the latitudes backward in the second paragraph ... Anyway, it is a moot point with the 1600 since the azimuth adjuster is in the back of the mount.

Mag. 7 Skies!

Howard Hedlund
Astro-Physics, Inc.
Phone: 815-282-1513
www.astro-physics.com<http://www.astro-physics.com/>
Please include this e-mail with your response.

P Consider the environment before printing this e-mail.


From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com] On Behalf Of Joe Zeglinski
Sent: Thursday, May 03, 2012 4:28 PM
To: ap-gto@yahoogroups.com
Subject: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?



Hi Chuck,

If at all possible ... it is best to AVOID using extension bars. I have
been advised by an expert, that he keeps his stack of cwts as close to the
upper bar as possible, and even retained his old, shorter, AP-1200 cwt bar.
He says that with the large mass of cwts down the bar, their "inertia" can
affect the "responsiveness", of fine guiding corrections.

Of course, this won't pose a problem for those at low latitudes, but
those in higher latitudes may have no choice but to use extensions, since
the cwt diameter can clip the mount post-meridian, especially the mount AZ
Adjuster knob, which sticks out a bit further, beyond the pier perimeter.

Some things to consider, before going for lighter weights further own the
bar, for the same leverage.
Joe Z.

-----Original Message-----
From: divenuts
Sent: Thursday, May 03, 2012 4:46 PM
To: ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>
Subject: Re: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?

Don't forget you can get an extention cwt bar, which cost much less than the
weights. If the 1600 couldn't use the 1200 weights..that would be a deal
breaker for me.
Chuck/divenuts







------------------------------------

To UNSUBSCRIBE, or for general information on the ap-gto list
see http://groups.yahoo.com/group/ap-gtoYahoo! Groups Links


Re: Need help with issue in RA guiding and Synchronous Pulseguide

parijat_singh
 

Hi Marj,

Thanks-
The moon is up, so I am not in a big hurry right now....and have time to do some more tests.

Regards
Parijat

--- In ap-gto@yahoogroups.com, Marj <marj@...> wrote:

Parijat,

Roland and I will be back in the office tomorrow and will review your information at that time. We have been on the road since NEAF.

Marjorie Christen


On May 3, 2012, at 4:28 PM, "photonphisher" <parijat_singh@...<mailto:parijat_singh@...>> wrote:




Hi Marj,
In the tracking curve I had uploaded, you can see PEM was always disabled (red button on the left). So I had ruled that out initially.

http://groups.yahoo.com/group/ap-gto/photos/album/104285095/pic/136447746/view

I think the gears are something I have not cleaned in a year (only lubricated). They look clean but it I understand from some of the posts here, it is suspect as it does not take much to cause a 5" irregularity.

Thanks again.
Parijat

--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "marjchristen" <marj@> wrote:


I suggest that you disable the PEM first and evaluate the performance. The rest of the steps you mention may not be needed if the problem is dur to an erroneous PEM curve.

Marj Christen

--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "photonphisher" <parijat_singh@> wrote:

Hi Marj and All,

Thanks a lot for your valuable suggestions. I now have a good list of things to check and ponder on.

I am planning to remove the 3 gears and carefully clean them well, and apply fresh grease.
Then double check the worm binding, backlash etc.
And disable PEM before checking the tracking.

Some homework to do :)

Thanks again, very much appreciate the help.

Parijat



--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "marjchristen" <marj@> wrote:

Dear Parijat,

Here is another idea. Do you have PEM set to yes? If you do, set it to "no" and see what happens. Sometimes, people create a bad periodic error correction model and then when the correction is activated, it causes strange movement.

Marj


--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "photonphisher" <parijat_singh@> wrote:

Hi Floyd
Yes it happens once per worm cycle. I monitored it for 5 cycles and showed up exactly at the same location each time. I can only think of the worm/block/assembly but I don't know the internals.

Last night I was seeing dumbells in 30 sec exposures if they fell in the right (or wrong) window. :(

Parijat



--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "bakersfieldbiker" <fblue@> wrote:

Hi,
Oh, I agree, it was probably not the situation, just was curious.
This only happens one time per worm cycle?
Floyd

--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "photonphisher" <parijat_singh@> wrote:

Hi Floyd,
I moved it 360degrees and it move smoothly with fingers. The mesh is optimum that there is little or no backlash. Also the screw on the spur gear is very tight.
That is the only gear in phase with the worm period and I felt nothing wrong with it physically and moving it full circle. No binding whatsoever. I would think binding would cause an issue much more prominent than 5arcsec.

Parijat


--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "bakersfieldbiker" <fblue@> wrote:

Hi Parijat,
Did you actually move the spur gear on the worm and this is where you say it moves smoothly? Just curious, because of an earlier thread where I described a binding in the worm gear bearing that I found on the AP-900.
Probably not related, but am wondering.
Floyd

--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "photonphisher" <parijat_singh@> wrote:

Hi David,
Thanks for your reply.
I have checked the gears for binding, etc. but they are all smoothly moving. Hence running out of ideas.

Parijat


--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, David Holko <dholko@> wrote:

Hello,

About a year ago I had a issue with my AP1200 RA motor. Howard got on
the phone with me and walked me thru a few checks. I am sure that once
the staff returns from NEAF you will be able to contact Howard and he
will do the same. It is not difficult to remove the top of the RA
housing and see and feel the gears and how the move with your fingers.
To see if there are binding.
I ended up sending the control box, RA housing and cables back to AP and
it all got sorted out. No issues since.

Dave







[Non-text portions of this message have been removed]


Re: Larger "diameter" Counterweights for AP-1600 ?

Howard Hedlund
 

Hi Joe,

I'm assuming you got the latitudes backward in the second paragraph ... Anyway, it is a moot point with the 1600 since the azimuth adjuster is in the back of the mount.

Mag. 7 Skies!

Howard Hedlund
Astro-Physics, Inc.
Phone: 815-282-1513
www.astro-physics.com<http://www.astro-physics.com/>
Please include this e-mail with your response.

P Consider the environment before printing this e-mail.


From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com] On Behalf Of Joe Zeglinski
Sent: Thursday, May 03, 2012 4:28 PM
To: ap-gto@yahoogroups.com
Subject: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?



Hi Chuck,

If at all possible ... it is best to AVOID using extension bars. I have
been advised by an expert, that he keeps his stack of cwts as close to the
upper bar as possible, and even retained his old, shorter, AP-1200 cwt bar.
He says that with the large mass of cwts down the bar, their "inertia" can
affect the "responsiveness", of fine guiding corrections.

Of course, this won't pose a problem for those at low latitudes, but
those in higher latitudes may have no choice but to use extensions, since
the cwt diameter can clip the mount post-meridian, especially the mount AZ
Adjuster knob, which sticks out a bit further, beyond the pier perimeter.

Some things to consider, before going for lighter weights further own the
bar, for the same leverage.
Joe Z.

-----Original Message-----
From: divenuts
Sent: Thursday, May 03, 2012 4:46 PM
To: ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>
Subject: Re: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?

Don't forget you can get an extention cwt bar, which cost much less than the
weights. If the 1600 couldn't use the 1200 weights..that would be a deal
breaker for me.
Chuck/divenuts


Re: Larger "diameter" Counterweights for AP-1600 ?

jjanusz@...
 

PlaneWave has 40 pound weights to fit the 1200 for $400.00 All stainless.

http://planewave.com/index.php?page=1&id0=5&id=7

Jim


---- Joe Zeglinski <J.Zeglinski@rogers.com> wrote:

Hi Chuck,

If at all possible ... it is best to AVOID using extension bars. I have
been advised by an expert, that he keeps his stack of cwts as close to the
upper bar as possible, and even retained his old, shorter, AP-1200 cwt bar.
He says that with the large mass of cwts down the bar, their "inertia" can
affect the "responsiveness", of fine guiding corrections.

Of course, this won't pose a problem for those at low latitudes, but
those in higher latitudes may have no choice but to use extensions, since
the cwt diameter can clip the mount post-meridian, especially the mount AZ
Adjuster knob, which sticks out a bit further, beyond the pier perimeter.

Some things to consider, before going for lighter weights further own the
bar, for the same leverage.
Joe Z.

-----Original Message-----
From: divenuts
Sent: Thursday, May 03, 2012 4:46 PM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?

Don't forget you can get an extention cwt bar, which cost much less than the
weights. If the 1600 couldn't use the 1200 weights..that would be a deal
breaker for me.
Chuck/divenuts



------------------------------------

To UNSUBSCRIBE, or for general information on the ap-gto list
see http://groups.yahoo.com/group/ap-gtoYahoo! Groups Links



Re: Larger "diameter" Counterweights for AP-1600 ?

Joe Zeglinski
 

Hi Chuck,

If at all possible ... it is best to AVOID using extension bars. I have been advised by an expert, that he keeps his stack of cwts as close to the upper bar as possible, and even retained his old, shorter, AP-1200 cwt bar. He says that with the large mass of cwts down the bar, their "inertia" can affect the "responsiveness", of fine guiding corrections.

Of course, this won't pose a problem for those at low latitudes, but those in higher latitudes may have no choice but to use extensions, since the cwt diameter can clip the mount post-meridian, especially the mount AZ Adjuster knob, which sticks out a bit further, beyond the pier perimeter.

Some things to consider, before going for lighter weights further own the bar, for the same leverage.
Joe Z.

-----Original Message-----
From: divenuts
Sent: Thursday, May 03, 2012 4:46 PM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?

Don't forget you can get an extention cwt bar, which cost much less than the
weights. If the 1600 couldn't use the 1200 weights..that would be a deal
breaker for me.
Chuck/divenuts


Re: Larger "diameter" Counterweights for AP-1600 ?

Christopher Erickson
 

It's called rigid foam and fiberglass tape!

I do it all the time.

Christopher Erickson
Consulting Engineer
Summit Kinetics
Waikoloa, HI 96738
www.summitkinetics.com

-----Original Message-----
From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com] On Behalf Of
andy
Sent: Thursday, May 03, 2012 10:49 AM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?


Subject: RE: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?



Just FYI, USPS Flat Rate Priority Mail within the 50 states goes up to 70
pounds and "If It Fits, It Ships!"

Can you imagine what would happen if one were to place a 70 lb. c'weight
in a thin cardboard box? It probably wouldn't make it out of the post
office.






------------------------------------

To UNSUBSCRIBE, or for general information on the ap-gto list
see http://groups.yahoo.com/group/ap-gtoYahoo! Groups Links



-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2012.0.1913 / Virus Database: 2425/4975 - Release Date: 05/03/12


Re: Need help with issue in RA guiding and Synchronous Pulseguide

 

Parijat,

Roland and I will be back in the office tomorrow and will review your information at that time. We have been on the road since NEAF.

Marjorie Christen

On May 3, 2012, at 4:28 PM, "photonphisher" <parijat_singh@yahoo.com<mailto:parijat_singh@yahoo.com>> wrote:




Hi Marj,
In the tracking curve I had uploaded, you can see PEM was always disabled (red button on the left). So I had ruled that out initially.

http://groups.yahoo.com/group/ap-gto/photos/album/104285095/pic/136447746/view

I think the gears are something I have not cleaned in a year (only lubricated). They look clean but it I understand from some of the posts here, it is suspect as it does not take much to cause a 5" irregularity.

Thanks again.
Parijat

--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "marjchristen" <marj@...> wrote:


I suggest that you disable the PEM first and evaluate the performance. The rest of the steps you mention may not be needed if the problem is dur to an erroneous PEM curve.

Marj Christen

--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "photonphisher" <parijat_singh@> wrote:

Hi Marj and All,

Thanks a lot for your valuable suggestions. I now have a good list of things to check and ponder on.

I am planning to remove the 3 gears and carefully clean them well, and apply fresh grease.
Then double check the worm binding, backlash etc.
And disable PEM before checking the tracking.

Some homework to do :)

Thanks again, very much appreciate the help.

Parijat



--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "marjchristen" <marj@> wrote:

Dear Parijat,

Here is another idea. Do you have PEM set to yes? If you do, set it to "no" and see what happens. Sometimes, people create a bad periodic error correction model and then when the correction is activated, it causes strange movement.

Marj


--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "photonphisher" <parijat_singh@> wrote:

Hi Floyd
Yes it happens once per worm cycle. I monitored it for 5 cycles and showed up exactly at the same location each time. I can only think of the worm/block/assembly but I don't know the internals.

Last night I was seeing dumbells in 30 sec exposures if they fell in the right (or wrong) window. :(

Parijat



--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "bakersfieldbiker" <fblue@> wrote:

Hi,
Oh, I agree, it was probably not the situation, just was curious.
This only happens one time per worm cycle?
Floyd

--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "photonphisher" <parijat_singh@> wrote:

Hi Floyd,
I moved it 360degrees and it move smoothly with fingers. The mesh is optimum that there is little or no backlash. Also the screw on the spur gear is very tight.
That is the only gear in phase with the worm period and I felt nothing wrong with it physically and moving it full circle. No binding whatsoever. I would think binding would cause an issue much more prominent than 5arcsec.

Parijat


--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "bakersfieldbiker" <fblue@> wrote:

Hi Parijat,
Did you actually move the spur gear on the worm and this is where you say it moves smoothly? Just curious, because of an earlier thread where I described a binding in the worm gear bearing that I found on the AP-900.
Probably not related, but am wondering.
Floyd

--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, "photonphisher" <parijat_singh@> wrote:

Hi David,
Thanks for your reply.
I have checked the gears for binding, etc. but they are all smoothly moving. Hence running out of ideas.

Parijat


--- In ap-gto@yahoogroups.com<mailto:ap-gto%40yahoogroups.com>, David Holko <dholko@> wrote:

Hello,

About a year ago I had a issue with my AP1200 RA motor. Howard got on
the phone with me and walked me thru a few checks. I am sure that once
the staff returns from NEAF you will be able to contact Howard and he
will do the same. It is not difficult to remove the top of the RA
housing and see and feel the gears and how the move with your fingers.
To see if there are binding.
I ended up sending the control box, RA housing and cables back to AP and
it all got sorted out. No issues since.

Dave


[Non-text portions of this message have been removed]




[Non-text portions of this message have been removed]


Re: Larger "diameter" Counterweights for AP-1600 ?

pgwsteve
 

In the A-P pdf file on the 1600, it states it has a 1.875" CW shaft, same as
the 900, 1200 and the optional Mach 1 shaft.



From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com] On Behalf Of
divenuts
Sent: Thursday, May 03, 2012 3:47 PM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?





Don't forget you can get an extention cwt bar, which cost much less than the

weights. If the 1600 couldn't use the 1200 weights..that would be a deal
breaker for me.
Chuck/divenuts

----- Original Message -----
From: "Joe Zeglinski" <J.Zeglinski@rogers.com
<mailto:J.Zeglinski%40rogers.com> >
To: <ap-gto@yahoogroups.com <mailto:ap-gto%40yahoogroups.com> >
Sent: Thursday, May 03, 2012 4:28 AM
Subject: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?

Roy,

Don't see where you got 110 lbs and AP-1200.
Granted, "old" AP-1200 carried that without breaking into a sweat, with
bar
space to spare.

But, my post was actually about the new AP-1600, I was actually
wondering about fitting 220 lbs. of "counterweights" on the STANDARD
bar,
to handle new maximum OTA load capacity on the AP-1600. I just can't
envisage 220 lbs made up from AP-18 lb cwts, and still being able to fit
on
an 18.5" bar.

Just as an exercise, to prove it:
Using my own "Counterweights Calculator" Spreadsheet, and configuring
a
220 lb (20" diameter OTA), on an AP-1200 as a stand-in, (since I don't
have
dimensions for the AP-1600 yet), I found that with just the standard 18.5"
bar alone, there is room for just six AP-18's - leaving ONLY 1/2 inch of
bar to spare.
Even with this fully occupied bar, the scope is still 106.33 lbs too
heavy!
If you want torque value, the 220 lb OTA would still be unbalanced by
1,978.74 inch-lbs.
So, that is why I can't see a 220 lb scope being able to use the "Standard
AP-1200 bar" (alone), and still using "Standard" AP counterweights.

However, to prove to myself the the benefit of new AP counterweights,
I
reran my calculations for the fully loaded 220 lb OTA (using AP-1200
dimensions as a stand-in)
- BUT this time ... I used the AP (8.75", 6.53 lb) BAR EXTENDER, with
"potentially NEW", AP 30 lb (7") & 40 lb (8") counterweights, to see what
it might take, to reach near equilibrium for such a heavy max'd out OTA.

Surprisingly, a 220 lb OTA would indeed balance, (with all cwts
positioned
at the BOTTOM of the bar), and using one of these set-ups:

(a) 8 x AP-18 lb + one AP-10 lb ... Standard + EXD BAR - 2.08 lbs
cwt-heavy, & 1.25" of empty bar remaining at the top
- or -
(b) 4 x AP-30 lb .......................... Standard + EXD BAR - 4.72
lbs cwt-heavy, & 15.25" of empty bar above all weights.
- or -
(c) 5 x AP-30 lb ........................... Standard + EXD BAR - 0.26
lbs cwt-heavy, & 7.25" of empty bar above all weights - BUT all cwts.
moved
up 5" from stop.
- or -
(d) 5 x AP-40 lb + one AP-18 lb ... Standard - NO EXD - 8.85 lbs
cwt-heavy, & 0.5" of empty bar to spare at the top of all cwts. - no
adjustment space!


So, if AP were to manufacture 7" diameter (30 lb) counterweights, just
for the "maximum load capacity" AP-1600 situation ... then configuration
(c), with five of these at middle of the (Extended) bar, would not only
perfectly balance a 220 lb (20" diameter) OTA, it would also leave about a
total of 12.5" of adjustment space on the bar, for accessories to be
added
or removed.

In fact, if all 5 of these 30-lb weights were positioned right at the
bottom of the bar, this set-up would be enough counterweight to carry &
balance another 44.56 lbs of CCD camera at the back of an RC-14 shaped
OTA. Of course, the OTA load would then be whopping 265 lbs, but Roland's
mounts seem to have "extra capacity" beyond spec.

NB: In my spreadsheet, I assumed a fictitious 20" diameter 220 lb OTA,
mounted on an "AP DOVELM162", for these calculations, with AP-1200
"Stiction" & size dimensions, and set-up for 44 deg. Latitude.
But, the results are indicative of what "might" be achieved.

Joe Z.

-----Original Message-----
From: roywellington
Sent: Thursday, May 03, 2012 12:37 AM
To: ap-gto@yahoogroups.com <mailto:ap-gto%40yahoogroups.com>
Subject: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?

Joe,

Balancing 110 pounds on an AP1200 with three weights not all the way out
the
extender and (eyeballing) space for maybe six more weights (true most
would
be close in but not all) seems to be quite enough except for one of those
squattish 24in Ricardi-Honders leviathans.

This almost certainly means the next R-H will be 20in only. Where do I
sign
up?

Roy



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Re: Larger "diameter" Counterweights for AP-1600 ?

andy <andy@...>
 

Subject: RE: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?



Just FYI, USPS Flat Rate Priority Mail within the 50 states goes up to 70
pounds and "If It Fits, It Ships!"

Can you imagine what would happen if one were to place a 70 lb. c'weight in a thin cardboard box? It probably wouldn't make it out of the post office.


Re: Larger "diameter" Counterweights for AP-1600 ?

divenuts
 

Don't forget you can get an extention cwt bar, which cost much less than the weights. If the 1600 couldn't use the 1200 weights..that would be a deal breaker for me.
Chuck/divenuts

----- Original Message -----
From: "Joe Zeglinski" <J.Zeglinski@rogers.com>
To: <ap-gto@yahoogroups.com>
Sent: Thursday, May 03, 2012 4:28 AM
Subject: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?


Roy,

Don't see where you got 110 lbs and AP-1200.
Granted, "old" AP-1200 carried that without breaking into a sweat, with bar
space to spare.

But, my post was actually about the new AP-1600, I was actually
wondering about fitting 220 lbs. of "counterweights" on the STANDARD bar,
to handle new maximum OTA load capacity on the AP-1600. I just can't
envisage 220 lbs made up from AP-18 lb cwts, and still being able to fit on
an 18.5" bar.

Just as an exercise, to prove it:
Using my own "Counterweights Calculator" Spreadsheet, and configuring a
220 lb (20" diameter OTA), on an AP-1200 as a stand-in, (since I don't have
dimensions for the AP-1600 yet), I found that with just the standard 18.5"
bar alone, there is room for just six AP-18's - leaving ONLY 1/2 inch of
bar to spare.
Even with this fully occupied bar, the scope is still 106.33 lbs too
heavy!
If you want torque value, the 220 lb OTA would still be unbalanced by
1,978.74 inch-lbs.
So, that is why I can't see a 220 lb scope being able to use the "Standard
AP-1200 bar" (alone), and still using "Standard" AP counterweights.

However, to prove to myself the the benefit of new AP counterweights, I
reran my calculations for the fully loaded 220 lb OTA (using AP-1200
dimensions as a stand-in)
- BUT this time ... I used the AP (8.75", 6.53 lb) BAR EXTENDER, with
"potentially NEW", AP 30 lb (7") & 40 lb (8") counterweights, to see what
it might take, to reach near equilibrium for such a heavy max'd out OTA.

Surprisingly, a 220 lb OTA would indeed balance, (with all cwts positioned
at the BOTTOM of the bar), and using one of these set-ups:

(a) 8 x AP-18 lb + one AP-10 lb ... Standard + EXD BAR - 2.08 lbs
cwt-heavy, & 1.25" of empty bar remaining at the top
- or -
(b) 4 x AP-30 lb .......................... Standard + EXD BAR - 4.72
lbs cwt-heavy, & 15.25" of empty bar above all weights.
- or -
(c) 5 x AP-30 lb ........................... Standard + EXD BAR - 0.26
lbs cwt-heavy, & 7.25" of empty bar above all weights - BUT all cwts. moved
up 5" from stop.
- or -
(d) 5 x AP-40 lb + one AP-18 lb ... Standard - NO EXD - 8.85 lbs
cwt-heavy, & 0.5" of empty bar to spare at the top of all cwts. - no
adjustment space!


So, if AP were to manufacture 7" diameter (30 lb) counterweights, just
for the "maximum load capacity" AP-1600 situation ... then configuration
(c), with five of these at middle of the (Extended) bar, would not only
perfectly balance a 220 lb (20" diameter) OTA, it would also leave about a
total of 12.5" of adjustment space on the bar, for accessories to be added
or removed.

In fact, if all 5 of these 30-lb weights were positioned right at the
bottom of the bar, this set-up would be enough counterweight to carry &
balance another 44.56 lbs of CCD camera at the back of an RC-14 shaped
OTA. Of course, the OTA load would then be whopping 265 lbs, but Roland's
mounts seem to have "extra capacity" beyond spec.

NB: In my spreadsheet, I assumed a fictitious 20" diameter 220 lb OTA,
mounted on an "AP DOVELM162", for these calculations, with AP-1200
"Stiction" & size dimensions, and set-up for 44 deg. Latitude.
But, the results are indicative of what "might" be achieved.

Joe Z.

-----Original Message-----
From: roywellington
Sent: Thursday, May 03, 2012 12:37 AM
To: ap-gto@yahoogroups.com
Subject: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?

Joe,

Balancing 110 pounds on an AP1200 with three weights not all the way out the
extender and (eyeballing) space for maybe six more weights (true most would
be close in but not all) seems to be quite enough except for one of those
squattish 24in Ricardi-Honders leviathans.

This almost certainly means the next R-H will be 20in only. Where do I sign
up?

Roy



------------------------------------

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see http://groups.yahoo.com/group/ap-gtoYahoo! Groups Links



Re: Need help with issue in RA guiding and Synchronous Pulseguide

parijat_singh
 

Hi Marj,
In the tracking curve I had uploaded, you can see PEM was always disabled (red button on the left). So I had ruled that out initially.

http://groups.yahoo.com/group/ap-gto/photos/album/104285095/pic/136447746/view

I think the gears are something I have not cleaned in a year (only lubricated). They look clean but it I understand from some of the posts here, it is suspect as it does not take much to cause a 5" irregularity.

Thanks again.
Parijat

--- In ap-gto@yahoogroups.com, "marjchristen" <marj@...> wrote:


I suggest that you disable the PEM first and evaluate the performance. The rest of the steps you mention may not be needed if the problem is dur to an erroneous PEM curve.

Marj Christen

--- In ap-gto@yahoogroups.com, "photonphisher" <parijat_singh@> wrote:

Hi Marj and All,

Thanks a lot for your valuable suggestions. I now have a good list of things to check and ponder on.

I am planning to remove the 3 gears and carefully clean them well, and apply fresh grease.
Then double check the worm binding, backlash etc.
And disable PEM before checking the tracking.

Some homework to do :)

Thanks again, very much appreciate the help.

Parijat



--- In ap-gto@yahoogroups.com, "marjchristen" <marj@> wrote:

Dear Parijat,

Here is another idea. Do you have PEM set to yes? If you do, set it to "no" and see what happens. Sometimes, people create a bad periodic error correction model and then when the correction is activated, it causes strange movement.

Marj


--- In ap-gto@yahoogroups.com, "photonphisher" <parijat_singh@> wrote:

Hi Floyd
Yes it happens once per worm cycle. I monitored it for 5 cycles and showed up exactly at the same location each time. I can only think of the worm/block/assembly but I don't know the internals.

Last night I was seeing dumbells in 30 sec exposures if they fell in the right (or wrong) window. :(

Parijat



--- In ap-gto@yahoogroups.com, "bakersfieldbiker" <fblue@> wrote:

Hi,
Oh, I agree, it was probably not the situation, just was curious.
This only happens one time per worm cycle?
Floyd

--- In ap-gto@yahoogroups.com, "photonphisher" <parijat_singh@> wrote:

Hi Floyd,
I moved it 360degrees and it move smoothly with fingers. The mesh is optimum that there is little or no backlash. Also the screw on the spur gear is very tight.
That is the only gear in phase with the worm period and I felt nothing wrong with it physically and moving it full circle. No binding whatsoever. I would think binding would cause an issue much more prominent than 5arcsec.

Parijat


--- In ap-gto@yahoogroups.com, "bakersfieldbiker" <fblue@> wrote:

Hi Parijat,
Did you actually move the spur gear on the worm and this is where you say it moves smoothly? Just curious, because of an earlier thread where I described a binding in the worm gear bearing that I found on the AP-900.
Probably not related, but am wondering.
Floyd

--- In ap-gto@yahoogroups.com, "photonphisher" <parijat_singh@> wrote:

Hi David,
Thanks for your reply.
I have checked the gears for binding, etc. but they are all smoothly moving. Hence running out of ideas.

Parijat


--- In ap-gto@yahoogroups.com, David Holko <dholko@> wrote:

Hello,

About a year ago I had a issue with my AP1200 RA motor. Howard got on
the phone with me and walked me thru a few checks. I am sure that once
the staff returns from NEAF you will be able to contact Howard and he
will do the same. It is not difficult to remove the top of the RA
housing and see and feel the gears and how the move with your fingers.
To see if there are binding.
I ended up sending the control box, RA housing and cables back to AP and
it all got sorted out. No issues since.

Dave


[Non-text portions of this message have been removed]


Re: Larger "diameter" Counterweights for AP-1600 ?

Christopher Erickson
 

Just FYI, USPS Flat Rate Priority Mail within the 50 states goes up to 70
pounds and "If It Fits, It Ships!"

The last time I shipped 50 pounds of couterweights from Hawaii to New York,
it cost me less than sixteen bucks.

This is absolutely the best way to ship counterweights.

International USPS Flat Rate Priority Mail is pretty amazingly cheap too,
but only goes up to 20 pounds. A 17 pound counterweight could be shipped
this way but probably nothing heavier.

Christopher Erickson
Consulting Engineer
Summit Kinetics
Waikoloa, HI 96738
www.summitkinetics.com

-----Original Message-----
From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com] On Behalf Of
andy
Sent: Thursday, May 03, 2012 9:36 AM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?


Subject: Re: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600
Lately there has been considerable discussion regarding c/weights. For
anyone interested I have the ultimate c'weight for sale. Ultimate bring that
it is 6 inches long, 6 inches in diameter with a 1.510 hole thru it with 2
1/2 13 locking screws at 45 degrees from each other and weighs according to
my bath room scale, 68.5 lbs. That's right 68.5 lbs.

I will not discuss the construction over the networks. If you would be
truly interested than call me for the particulars at 575-437-4233 after
10:00 AM and up till midnight, Keep in mind that shipping cost will be
horrible. Again DO NOT TRY TO CONTACT ME FOR INFO THRU THE NEWSGROUPS as I
will not respond to any questions posted to the news groups.

Andy






------------------------------------

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see http://groups.yahoo.com/group/ap-gtoYahoo! Groups Links



-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2012.0.1913 / Virus Database: 2425/4975 - Release Date: 05/03/12


Re: Larger "diameter" Counterweights for AP-1600 ?

 

Hi Joe,

We will evaluate the need for an additional cwt suitable for the increased capacity of the 1600.

Marjorie Christen

On Apr 30, 2012, at 1:31 PM, "Joe Zeglinski" <J.Zeglinski@rogers.com<mailto:J.Zeglinski@rogers.com>> wrote:



Hi Marj,

Looking at the new AP-1600 picture, the RA axle section (housing) seems truncated shorter than on an AP-1200, so the standard cwt bar might also sit a few inches higher up the axle, thus less leverage. In order to be able to actually mount “upto” a gargantuan 220 lb (with accessories) OTA, and in order to still have enough bar space for all its counterweights, have you considered offering an 7-inch “diameter” cwt instead of limiting it to the current AP standard 6" (nominal) inch?

Based on past calculations, for the same thickness, an 7” diameter cwt should give you a 30 lb weight, or an 8” diameter 40 lb cwt. - in the same space and bar hole diameter – assuming larger stainless steel bar stock is available.
However, steel toe construction boots might become a safety accessory for such heavy weights

The downside might be that at higher latitude set-ups, the larger cwt might approach the mount a bit closer, when past the meridian.

Joe Z.


Re: Larger "diameter" Counterweights for AP-1600 ?

andy <andy@...>
 

Subject: Re: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600
Lately there has been considerable discussion regarding c/weights. For anyone interested I have the ultimate c'weight for sale. Ultimate bring that it is 6 inches long, 6 inches in diameter with a 1.510 hole thru it with 2 1/2 13 locking screws at 45 degrees from each other and weighs according to my bath room scale, 68.5 lbs. That's right 68.5 lbs.

I will not discuss the construction over the networks. If you would be truly interested than call me for the particulars at 575-437-4233 after 10:00 AM and up till midnight, Keep in mind that shipping cost will be horrible. Again DO NOT TRY TO CONTACT ME FOR INFO THRU THE NEWSGROUPS as I will not respond to any questions posted to the news groups.

Andy


Re: Larger "diameter" Counterweights for AP-1600 ?

Joe Zeglinski
 

Thanks again, Fernando,

Got an email reply from PlaneWave, and just as I calculated - their #600111 AP-style 40 lb couterweight is indeed 8" outer diameter, by 3" thick, with an aluminum lock knob. That should shorten the required length of AP cwt bar for heavier OTA's - though shifting or lifting such a heavy weight can be a bit challenging.

I am confident that the AP cwt bar threads are "strong enough" to hold all this counterweight, and more.

I asked, but - unfortunately - PlaneWave has no plans for a 30 lb cwt. .

Joe Z.

-----Original Message-----
From: Fernando Rivera
Sent: Thursday, May 03, 2012 7:12 AM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?

Hi, Joe

FYI, if someone wishes to use heavier counterweights to fit the 1.875" ctw shaft, there are 21.7# weights from Robin Casady, & 40# weights from "PlaneWave Instruments", available for purchase.

Best regards

Fernando


Re: Larger "diameter" Counterweights for AP-1600 ?

 

The photo shows the 1600 w/ the new 175mm StarFire, 305mm Riccardi-Honders and 305mm Mak-Cas on a special plate we made for the test. The instrument weight exceeded 220 lbs. It was quite impressive! Both the mount and 175 were under test at the time and were not painted.

I will try to post the photo tomorrow. Roland and I are on the road outside Toledo, heading home. We spent a few days with his family in NY after NEAF. We will be in the office tomorrow.

Marj Christen

--- In ap-gto@yahoogroups.com, "Dean S" <dean@...> wrote:

Marj showed me a picture of the mount while it was being tested. They had
the 175 and RH, and maybe even something else on it with a long shaft full
of weights. Looked like it had an extension on it best I could tell. She
said the mount performed perfectly loaded to the max.

And what was cool looking was that the new scope and mount where still
unfinished, bare aluminum. Perhaps she or Roland could post that picture??

Dean



-----Original Message-----
From: Joe Zeglinski
Sent: Thursday, May 03, 2012 4:28 AM
To: ap-gto@yahoogroups.com
Subject: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?

Roy,

Don't see where you got 110 lbs and AP-1200.
Granted, "old" AP-1200 carried that without breaking into a sweat, with bar
space to spare.

But, my post was actually about the new AP-1600, I was actually
wondering about fitting 220 lbs. of "counterweights" on the STANDARD bar,
to handle new maximum OTA load capacity on the AP-1600. I just can't
envisage 220 lbs made up from AP-18 lb cwts, and still being able to fit on
an 18.5" bar.

Just as an exercise, to prove it:
Using my own "Counterweights Calculator" Spreadsheet, and configuring a
220 lb (20" diameter OTA), on an AP-1200 as a stand-in, (since I don't have
dimensions for the AP-1600 yet), I found that with just the standard 18.5"
bar alone, there is room for just six AP-18's - leaving ONLY 1/2 inch of
bar to spare.
Even with this fully occupied bar, the scope is still 106.33 lbs too
heavy!
If you want torque value, the 220 lb OTA would still be unbalanced by
1,978.74 inch-lbs.
So, that is why I can't see a 220 lb scope being able to use the "Standard
AP-1200 bar" (alone), and still using "Standard" AP counterweights.

However, to prove to myself the the benefit of new AP counterweights, I
reran my calculations for the fully loaded 220 lb OTA (using AP-1200
dimensions as a stand-in)
- BUT this time ... I used the AP (8.75", 6.53 lb) BAR EXTENDER, with
"potentially NEW", AP 30 lb (7") & 40 lb (8") counterweights, to see what
it might take, to reach near equilibrium for such a heavy max'd out OTA.

Surprisingly, a 220 lb OTA would indeed balance, (with all cwts positioned
at the BOTTOM of the bar), and using one of these set-ups:

(a) 8 x AP-18 lb + one AP-10 lb ... Standard + EXD BAR - 2.08 lbs
cwt-heavy, & 1.25" of empty bar remaining at the top
- or -
(b) 4 x AP-30 lb .......................... Standard + EXD BAR - 4.72
lbs cwt-heavy, & 15.25" of empty bar above all weights.
- or -
(c) 5 x AP-30 lb ........................... Standard + EXD BAR - 0.26
lbs cwt-heavy, & 7.25" of empty bar above all weights - BUT all cwts. moved
up 5" from stop.
- or -
(d) 5 x AP-40 lb + one AP-18 lb ... Standard - NO EXD - 8.85 lbs
cwt-heavy, & 0.5" of empty bar to spare at the top of all cwts. - no
adjustment space!


So, if AP were to manufacture 7" diameter (30 lb) counterweights, just
for the "maximum load capacity" AP-1600 situation ... then configuration
(c), with five of these at middle of the (Extended) bar, would not only
perfectly balance a 220 lb (20" diameter) OTA, it would also leave about a
total of 12.5" of adjustment space on the bar, for accessories to be added
or removed.

In fact, if all 5 of these 30-lb weights were positioned right at the
bottom of the bar, this set-up would be enough counterweight to carry &
balance another 44.56 lbs of CCD camera at the back of an RC-14 shaped
OTA. Of course, the OTA load would then be whopping 265 lbs, but Roland's
mounts seem to have "extra capacity" beyond spec.

NB: In my spreadsheet, I assumed a fictitious 20" diameter 220 lb OTA,
mounted on an "AP DOVELM162", for these calculations, with AP-1200
"Stiction" & size dimensions, and set-up for 44 deg. Latitude.
But, the results are indicative of what "might" be achieved.

Joe Z.

-----Original Message-----
From: roywellington
Sent: Thursday, May 03, 2012 12:37 AM
To: ap-gto@yahoogroups.com
Subject: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?

Joe,

Balancing 110 pounds on an AP1200 with three weights not all the way out the
extender and (eyeballing) space for maybe six more weights (true most would
be close in but not all) seems to be quite enough except for one of those
squattish 24in Ricardi-Honders leviathans.

This almost certainly means the next R-H will be 20in only. Where do I sign
up?

Roy



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Re: Need help with issue in RA guiding and Synchronous Pulseguide

 

I suggest that you disable the PEM first and evaluate the performance. The rest of the steps you mention may not be needed if the problem is dur to an erroneous PEM curve.

Marj Christen

--- In ap-gto@yahoogroups.com, "photonphisher" <parijat_singh@...> wrote:

Hi Marj and All,

Thanks a lot for your valuable suggestions. I now have a good list of things to check and ponder on.

I am planning to remove the 3 gears and carefully clean them well, and apply fresh grease.
Then double check the worm binding, backlash etc.
And disable PEM before checking the tracking.

Some homework to do :)

Thanks again, very much appreciate the help.

Parijat



--- In ap-gto@yahoogroups.com, "marjchristen" <marj@> wrote:

Dear Parijat,

Here is another idea. Do you have PEM set to yes? If you do, set it to "no" and see what happens. Sometimes, people create a bad periodic error correction model and then when the correction is activated, it causes strange movement.

Marj


--- In ap-gto@yahoogroups.com, "photonphisher" <parijat_singh@> wrote:

Hi Floyd
Yes it happens once per worm cycle. I monitored it for 5 cycles and showed up exactly at the same location each time. I can only think of the worm/block/assembly but I don't know the internals.

Last night I was seeing dumbells in 30 sec exposures if they fell in the right (or wrong) window. :(

Parijat



--- In ap-gto@yahoogroups.com, "bakersfieldbiker" <fblue@> wrote:

Hi,
Oh, I agree, it was probably not the situation, just was curious.
This only happens one time per worm cycle?
Floyd

--- In ap-gto@yahoogroups.com, "photonphisher" <parijat_singh@> wrote:

Hi Floyd,
I moved it 360degrees and it move smoothly with fingers. The mesh is optimum that there is little or no backlash. Also the screw on the spur gear is very tight.
That is the only gear in phase with the worm period and I felt nothing wrong with it physically and moving it full circle. No binding whatsoever. I would think binding would cause an issue much more prominent than 5arcsec.

Parijat


--- In ap-gto@yahoogroups.com, "bakersfieldbiker" <fblue@> wrote:

Hi Parijat,
Did you actually move the spur gear on the worm and this is where you say it moves smoothly? Just curious, because of an earlier thread where I described a binding in the worm gear bearing that I found on the AP-900.
Probably not related, but am wondering.
Floyd

--- In ap-gto@yahoogroups.com, "photonphisher" <parijat_singh@> wrote:

Hi David,
Thanks for your reply.
I have checked the gears for binding, etc. but they are all smoothly moving. Hence running out of ideas.

Parijat


--- In ap-gto@yahoogroups.com, David Holko <dholko@> wrote:

Hello,

About a year ago I had a issue with my AP1200 RA motor. Howard got on
the phone with me and walked me thru a few checks. I am sure that once
the staff returns from NEAF you will be able to contact Howard and he
will do the same. It is not difficult to remove the top of the RA
housing and see and feel the gears and how the move with your fingers.
To see if there are binding.
I ended up sending the control box, RA housing and cables back to AP and
it all got sorted out. No issues since.

Dave


[Non-text portions of this message have been removed]


Re: Larger "diameter" Counterweights for AP-1600 ?

Joe Zeglinski
 

Thanks Fernando,

That is good information.
While looking for heavier counterweights for my RC14, I did buy a couple of those 21.7 lb Cassady's. I didn't know that Planewave has the 40's, for the same AP shaft diameter.I thought they used a different shaft size. I will check into that.

Surely, there must be "uncommon non-advertised" huge cwts for the AP-3600. That should help solve the (potential) AP-1600 desire of a much larger cwt on a short AP standard bar.

Joe

-----Original Message-----
From: Fernando Rivera
Sent: Thursday, May 03, 2012 7:12 AM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] Re: Larger "diameter" Counterweights for AP-1600 ?

Hi, Joe

FYI, if someone wishes to use heavier counterweights to fit the 1.875" ctw shaft, there are 21.7# weights from Robin Casady, & 40# weights from PlaneWave Instruments, available for purchase.

Best regards

Fernando

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